The disclosed embodiments relate to analyzing the performance of a wireless communications network and adjusting parameters in the wireless communications network. Wireless communications systems using cellular or Personal Communication Services (PCS) devices vary in performance from the point of view of the device user. For example, a cellular phone user may experience very good call quality or less than satisfactory call quality depending upon location and/or time of day. Entities that design, construct, and maintain wireless communications networks are very motivated to provide the best service to as many users as possible all of the time. This can be difficult due to the nature of the networks. For example, there is a finite number of physical network components, such as cell sites, PCS sites (or base stations) and repeaters in the network. The location of the components affects the performance of the network. The assignment of network parameters, such as power of individual network components, and frequencies assigned to geographical areas, also affects the performance of the network. Assigning network parameters is challenging because there is no static solution. Factors such as varying use of the network over time require the finite resources to be distributed differently over time to maximize performance for current users. The “best” network configuration is thus a moving target. Because the experience of the end user is what really matters, performance engineers attempt to collect and analyze data that reflects the end user's experience of the network.
Traditional approaches to network analysis are very expensive and time consuming. In addition, traditional approaches do not allow the network administrator to react very quickly to network deficiencies. One traditional method of collecting network performance data is drive testing. Drive testing involves a truck full of sophisticated equipment driving through areas covered by a wireless network service provider. A performance engineer on the truck utilizes special equipment to make test calls makes a call to a fixed location. The equipment can send a variety of performance data to the fixed location on demand. During the call, the fixed location collects performance data from the telephone and the network, such as signal strength, and other measures. Thus, data collected by drive testing provides a fairly precise location for data gathered. The data collected can be associated with the general area the truck is passing through, and thus the mobile data reflects the user's experience in the wireless network. Data collected by drive testing is analyzed to determine adjustments to be made to the network parameters. Changes to network parameters include increasing the power of certain components to reduce the number of dropped calls, reducing the transmitting power to reduce interference, and changing frequency assignments to cell site and sectors.
Traditional drive testing is very expensive. Also, it can be too expensive to gather enough data to be statistically relevant. Another disadvantage is that gathering data can take so long that the data is not very useful. Obviously, a limited number of trucks are deployed at any time, so that any characterization of the network resulting from the drive testing is incomplete. In addition, it takes time to deploy drive testing trucks, collect data, and make network parameter adjustments. By the time the adjustments are made, the network may require different adjustments. In addition, the results of the adjustment are difficult to determine quickly.
Another traditional method of collecting network performance data is using data generated by switch statistics software. Switches in the network routinely capture data related to calls. This data reflects performance of the network, but lacks location information. This method is less expensive than drive testing, and is a faster process. Because of the lack of location information, however, only broad, coarse adjustments can be made based on the data analyzed. Because this method does not enable finer adjustments to be made, or even to be detected, this method is not helpful in solving network performance problems that are not easily seen or are geographically limited.
Efforts have been made to merge the data from the switch and data from drive testing, but this is difficult. Several software vendors sell products that analyze wireless network performance data, display results, and make suggestions regarding network design. The data available still has the limitations discussed above.
Overall, there is a need for improved performance data collection and analysis in wireless communications networks.
Note: the headings provided herein are for convenience and do not necessarily affect the scope or interpretation of the invention.